I. Field of the Invention
This invention relates generally to medical snap connectors which are connectable to ball-stud patient engaging electrodes and, more particularly, to a snap connector having an improved contact area engaging the received male stud.
II. Discussion of the Prior Art
In recent years a variety of medical snap connectors and associated male studs have been introduced into the medical field. Generally, electrodes containing a male terminal, or ball-stud, are adhesively secured to the skin of a patient. The stud is adapted to snap into a female terminal in the connector and is typically shaped in accordance with ANSI standards. A conductive lead wire is connected to the female terminal and completes an electrical path between the male stud and an electromedical device such as an electrocardiograph. The stud portion of the electrode is generally connected to a metallic plate which is, in turn, connected to the patient's skin by means of an electrically conductive material such as an electrolyte gel.
The major drawback associated with various snap connectors is that the quality of a mechanical connection between the female snap connector and the male stud is degraded through extensive usage. Further, these female snap-on connectors are rather complex in design and relatively expensive to manufacture. The conductors are usually manually soldered or welded to the female terminal which is time consuming, occasionally unreliable, and a rather difficult process to automate.
U.S. Pat. No. 4,671,591, issued to Archer, teaches an electrical connector having a retainer spring captured in a cavity and engaging a stud. This connector requires soldering of the spring to the conductor which is time consuming. Further, only one contact region between the conductor and the stud is provided.
U.S. Pat. No. 3,750,094, issued to Zenkich, teaches an electrical connector having a spring compressed in a bore for engaging a narrowed portion of a male stud. The drawback of this connector is that should one of the spring arms fail due to excessive wear, for example, the whole connector is nonfunctional. Further, only one contact region is established between the spring and the stud.
U.S. Pat. No. 4,112,941, issued to Larimore, teaches a snap-on connector with a magnetic element. This connector has only one contact region, and further, teaches a lead wire which is only electrically connected to shell 26.
U.S. Pat. No. 4,460,231, issued to Muz, teaches an electrical connector having a spring element with a longitudinal slit. This connector also has only one contact region.